A PASTOR working in the mines of eastern Sierra Leone has unearthed a 706-carat diamond, a discovery that experts said could be the 10th largest stone ever found.

The huge rock was extracted by Emmanuel Momoh, one of thousands who seek their fortunes in the informal mining sector that dominates the diamond-rich Kono region.

The gem, a bit smaller than a hockey puck, is the second largest diamond found in Sierra Leone and the largest uncut diamond found in more than four decades.

As a self-employed miner with a valid government permit, Momoh is entitled to the proceeds of any future sale, except four per cent the government takes for valuation and export, according to the law, plus an undetermined level of income tax.

Sierra Leone's President Ernest Bai Koroma handles the diamond found by a local pastor.

But Momoh has instead handed it to the government, saying he hopes it helps to boost recent development in his impoverished nation.

It’s the largest uncut diamond found in more than four decades. Picture: SLBC via AP